Summary

Gene regulation has turned out to be a surprisingly complex process governed by various types of regulatory DNA, which may lie deep in the wilderness of so-called junk DNA that lies between genes. Far from being humble messengers, RNAs of all shapes and sizes are actually powerful players in how genomes operate. Finally, there's been increasing recognition of the widespread role of chemical alterations called epigenetic factors that can influence the genome across generations without changing the DNA sequence itself. The scope of this "dark genome" became apparent in 2001, when the human genome sequence was first published.